# CVE-2026-111643: Misaka Danmu Server through 2.8.9 Authentication Bypass via Config-History Rollback

> Unauthenticated attackers can bypass authentication by modifying configuration keys via an unprotected endpoint, gaining administrator access to the Misaka Danmu Server.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** GHSA-h9w3-vw4p-h6vw

## What is CVE-2026-111643?

CVE-2026-111643 is a critical authentication bypass vulnerability in l429609201 misaka_danmu_server, published on 16 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Misaka Danmu Server through 2.8.9 contains an authentication bypass vulnerability that allows unauthenticated attackers to write arbitrary configuration keys via the unprotected POST /api/ui/config-history/rollback endpoint. Attackers can set the ipWhitelist key to their own /32 address, or alter trustedProxies and webhookApiKey, to access every protected endpoint as the administrator.

Weakness: CWE-306 (Missing Authentication for Critical Functionality)

## Which versions are affected by CVE-2026-111643?


## How do I fix CVE-2026-111643?

No fix has been published for CVE-2026-111643 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-111643 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111643 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111643 and fix it if it is affected.

What it is: CVE-2026-111643 is a critical authentication bypass vulnerability in l429609201 misaka_danmu_server, published on 16 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111643 exists.

Affected product: l429609201 misaka_danmu_server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-111643/ (Markdown: https://insights.sbomify.com/CVE-2026-111643/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111643
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111643
- OSV: https://osv.dev/vulnerability/CVE-2026-111643

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111643/
Summaries are generated and may contain mistakes; the official description above is the record.